The head engineer/designer left OS and WENT ON BOARD TO THUNDER TIGER. He took "his" designs with him!

The TT and OS are virtually the same engine, (the newer ones)

I have a KYOSHO CAP 232 ARF and have ran BOTH engines in this plane, I FLEW IT WITH 10x6,10x10,11x5,11x6 AND 11X7 PROPS (MANY DIFFERENT BRANDS) and found absolutely NO difference except the TT had a LITTLE better verticle. ( I NOW FLY IT WITH A k&b 48) My personal preference (BETWEEN THE tt AND os)is the THUNDER TIGER and at a CONSIDERABLE SAVINGS FOR THE WALLET!
I have a "MACS" tuned pipe that I have ran on the THUNDER TIGER and it turns this engine into a rocket engine, unreal power gains! I like it so well I just bought a SPECTRUM just for this engine! (because of the tunnel for the tuned pipe)
Yes I do build but I hold down two jobs and don't have the time to build as I like so I depend on ARFS.

OS has gotten way out of line with the price of their engines just because at ONE TIME they were the "KINGS" of small engines. not so any more! many engine companies are running them competition in power and especially price! I do not have a thing against OS, so please do not take me wrong, I fly OS bushing engines in my trainers, and my grandsons sport planes. (GOLDBERG EAGLE,GLOBAL RIGHT FLYER AND HANGER NINE ADVANCE all have OS 46 LA engines) very dependable powerful engines for bushing engines! very easy to set up! very consistant for beginners! But when it comes to powerful/ dependable then I vote for either OS or THUNDER TIGER, But when price comes into play, THUNDER TIGER TAKES OS HANDS DOWN!
You can buy OS (NORMALLY $119.95)and pay an addional $50.00 for the name, or buy a THUNDER TIGER ($69.95)(virtually the same engine)and pick up 5 gallons of 15% fuel to run it with for the same price! hmmmmm And even if you do find it for less differential in price it's still a lot of other needed stuff! I'll have to think about that one for a while... "NO BRAINER!"

BY THE WAY, THERE WAS A TIME NOT TOO LONG AGO I WOULDN'T HAVE CONSIDERED ANYTHING EXCEPT OS..(I have an OS 70 4 stroke,OS 91 4 stroke,3 os 40 FPs 3 OS 46 LAs 1 OS 25FP and I know there is more there but just can't think of them right now) THE OS 52 4 STROKER IS ANOTHER I HAVE, Yes it's a power house and real smooth. There's a very good OS engine.

Now I want power, dependability and "price"!

If you want dependle power, GO THUNDER TIGER, If you want all out power, go JETT, NELSON or yes ROSSI! (BUT BE PREPARED TO TUNE!)

CLARENCE LEE is an engine reviewer and rebuilder,he's reviewing for RCM now. He used to take K&B engines and make them "sing" He's also done some designing! he's looked at very highly in the R/C engine industry/hobby on his engine knowledge. ( you can contact RCM and they will hook you up with the months these engines were reviewed and you can purchase the back editions) OR MAYBE ONLINE? BUT his reviews are done on the test stand!!


Someone needs to get their local CLUB involved in this TT/OS argument, not one person but a group! they could buy both new,break them as per mgr. instructions to the "T", put them into something such as a STICK, run THE SAME prop,fuel etc. at the same altitude,humidity and temperature. having the same specifications for tuning : ie. the same way of leaning the engines out for realtime flight. (300 rpm rich with pinch test or whatever, but the same TACH ETC)

The "seed" is planted, now GO FOR IT!!!!!

RON in NEVADA